The present invention relates to an endoscope for bile duct and pancreatic duct for non-invasive endoscopic observation of bile duct and pancreatic duct.
An endoscope of double-scope system is already known. This consists of a mother endoscope having an insertion unit, which can be inserted into duodenum, and of a daughter endoscope having an insertion unit, which can be introduced by transpapillary insertion through a forceps channel of the above insertion unit. In such system of endoscope, the interior of the bile duct and pancreatic duct can be observed by introducing the insertion unit of the daughter endoscope directly into papilla through forceps channel of the mother endoscope. However, it is necessary to have perfusion to clean up the interior of the region to be observed for perfect examination of bile duct and pancreatic duct. For this purpose, the insertion unit of the daughter endoscope must have a path, through which physiological saline for perfusion can be sent, and, accordingly, the insertion unit must have larger diameter. The tip of the insertion unit of such daughter endoscope cannot be inserted conveniently into papilla unless it is bent toward the desired direction. Consequently, it is designed in such manner that the tip can be bent upward or downward.
In the conventional double scope system, the tip of the insertion unit of the daughter endoscope is directly inserted into papilla. To ensure the positive insertion, the tip must be bent. Also, it is necessary to provide a path to send physiological saline for perfusion and a hole for accommodating small surgical tools. Thus, it must be relatively large in diameter (outer diameter: 3.5 mm). When it is to be inserted into pancreatic duct, which is smaller than bile duct, it is very difficult to place the tip of the insertion unit with outer diameter of 3.5 mm into the duct, and it requires skill. It is also very likely that the papilla is injured by the tip of the insertion unit.
The object of the present invention is to provide an endoscope for bile duct and pancreatic duct, in which the insertion unit of the daughter endoscope can be easily and safely inserted into papilla as well as into bile duct and pancreatic duct and the insertion unit of the daughter endoscope is used only for observation with no need for bending and for providing the path to send saline. Another object of the invention is to offer an endoscope for bile duct and pancreatic duct, in which it is possible to inject physiological saline for perfusion and also to insert various types of tools.
To achieve the objects as described above, the first invention consists of a mother endoscope having an insertion unit to be inserted into duodenum, a forceps channel of the insertion unit and an insertion hole connected with the forceps channel, of a flexible guide tube, which is to be inserted into bile duct and pancreatic duct from papilla through the forceps channel and into which the insertion unit of the daughter endoscope is inserted, and of a flexible core bar, which is mounted removably on one end of the guide tube, is inserted into the guide tube and has such length that its tip does not protrude from the guide tube. The second invention consists of a mother endoscope, of which the insertion unit having a forceps channel can be inserted into duodenum, and of a daughter endoscope, of which the insertion unit is guided by the flexible guide tube from the forceps channel of the mother endoscope and is inserted into bile duct and pancreatic duct. Two or more fixing tubes with different diameters are concentrically provided to cover the insertion unit on the base end of the insertion unit of the daughter endoscope, and the fixing tube corresponding to the guide tube, which is selected through an adaptor according to the diameter of a guide tube selected from two or more guide tubes having different diameters and inserted into bile duct and pancreatic duct from the forceps channel of the mother endoscope, is connected with the guide tube. The third invention consists of a flexible guide tube, which can be inserted into bile duct and pancreatic duct through the forceps channel through the insertion hole of the mother endoscope with its insertion unit placed into duodenum, of a fixing tube to be mounted on the base end of the insertion unit of the daughter endoscope, and of an adaptor, both ends of which are mounted on the fixing tube and on the guide tube, into which the insertion unit of the daughter endoscope is inserted. When the other end of the adaptor is mounted on the guide tube, the tip of the insertion unit inserted into the guide tube of the daughter endoscope is roughly aligned with the tip of the guide tube and does not protrude. Further, the fourth invention consists of a flexible first guide tube to be inserted from the insertion hole of the mother endoscope through the forceps channel into bile duct and pancreatic duct, of a junction tube to be connected with the first guide tube, of a flexible second guide tube, which has larger diameter than the first guide tube, is guided by the junction tube and the first guide tube and is inserted into bile duct and pancreatic duct, of a fixing tube to be mounted on the base end of the insertion unit, which is placed into the second guide tube of the daughter endoscope, of an enclosure unit provided on the base end of the insertion unit of the daughter endoscope to close up the gap between the fixing tube and the insertion unit of the daughter endoscope, and of an adaptor, both ends of which are mounted on the second guide tube and the fixing tube after the first guide tube and the junction tube have been withdrawn from the second guide tube, guided by the first guide tube and inserted into bile duct and pancreatic duct. It is provided at least with a cross passage in it and is designed in such manner that forceps or other tool and saline can be inserted or injected into bile duct and pancreatic duct through the second guide tube from the cross tube of the adaptor, comprising a straight tube and one or two or more cross tubes.
In the first invention, a core bar mounted on the mounting unit from the insertion hole of the mother endoscope is placed into the guide tube. This guide tube containing core bar is introduced into the forceps channel in order to insert the guide tube into bile duct and pancreatic duct. After observing duodenum and confirming the papilla by the tip of the insertion unit of the mother endoscope, the tip of the guide tube containing core bar is inserted into bile duct or pancreatic duct through papilla by manipulating the forceps elevator. Since a flexible core bar is contained in the guide tube, neither twisting nor turning occurs within the forceps channel, and positive insertion can be achieved straight toward the papilla. By fluoroscopy after the insertion, the core bar can be seen as image, and it is possible to confirm how far the guide tube has been inserted. If the core bar is withdrawn from the guide tube, it is possible to observe the interior of bile duct and pancreatic duct by placing the insertion unit of the daughter endoscope into the guide tube. In this case, it is possible to provide better observation through the supply of physiological saline through the gap between the insertion unit of the daughter endoscope and the guide tube.
When bile duct or pancreatic duct is observed by the second invention, the tip of the insertion unit of the mother endoscope is introduced perorally into duodenum and the position of papilla is confirmed. Then, a guide tube having such diameter that it is easy to insert into papilla is inserted into the forceps channel, and the tip of the guide tube is inserted again toward the papilla by utilizing the forceps elevator mounted on the tip of the insertion unit of the mother endoscope. Because the guide tube has full flexibility, it can be inserted into bile duct or pancreatic duct through papilla without injuring it. Also, the guide tube can be designed with smaller diameter because it is merely to accommodate the insertion unit of daughter endoscope for the purpose of observation only (neither the passage nor the forceps channel being required), and it can be inserted into papilla without difficulty. When the guide tube is inserted into bile duct or pancreatic duct through papilla, the insertion unit of the daughter endoscope is placed into the guide tube. Thus, physiological saline can be supplied through the gap between the insertion unit of daughter endoscope and the guide tube. In this case, an appropriate tube is chosen from two or more fixing tubes, and these tubes are connected through the adaptor, and saline is supplied by the use of this adaptor. Further, when a guide tube with larger diameter is used, the guide tube with larger diameter is inserted into bile duct and pancreatic duct using a guide tube of smaller diameter, and the latter is then withdrawn. A fixing tube corresponding to the guide tube with larger diameter is selected, and these tube are connected through adaptor to have communication with each other, and various types of tools can be inserted by utilizing the adaptor.
In the third invention, the papilla of duodenum is confirmed by the tip of the insertion unit of the mother endoscope. Then, the guide tube is introduced from the insertion hole into the forceps channel, and the tip of the guide tube is inserted toward papilla by manipulating the forceps elevator at the tip of the insertion unit. When the guide tube is inserted into bile duct or pancreatic duct through papilla, the insertion unit of the daughter endoscope is placed into the guide tube. When the other end of the adaptor is mounted on the guide tube, the tip of the insertion unit is roughly aligned with the tip of the guide tube. Hence, bile duct or pancreatic duct is not injured by the tip of fiberscope. Also, in order to ensure clear observation by the fiberscope, it is possible to inject physiological saline from the adaptor into the guide tube.
In the fourth invention, the papilla of duodenum is confirmed by the tip of the insertion unit of the mother endoscope. Then, the first guide tube with smaller diameter is placed from the insertion hole through the forceps channel, and the tip of the first guide tube is inserted toward papilla by manipulating the forceps elevator at the tip of the insertion unit. When the first guide tube is inserted into bile duct or pancreatic duct through papilla, the junction tube is connected with this first guide tube, and the second guide tube is inserted into bile duct or pancreatic tube, being guided by these tubes. Because the first guide tube has such diameter as to facilitate the insertion even into pancreatic duct, it is possible to insert it easily using the mother endoscope with narrower thinner forceps channel. The mother endoscope having the forceps channel with smaller diameter is withdrawn, and the junction tube and the first guide tube are inserted into the forceps channel of another mother endoscope having forceps channel of sufficiently larger diameter to accommodate the second guide tube. Thus, the mother endoscope can be replaced. Next, the insertion unit of the daughter endoscope can be placed into the second guide tube. When the other end of the adaptor is mounted on the second guide tube, injury to bile duct and pancreatic duct the tip of the insertion unit can be prevented through such arrangement that the tip of the insertion unit is roughly aligned with the tip of the second guide tube and does not protrude. Since the gap between the second guide tube and the insertion unit is relatively wide, a tool can be inserted or physiological saline can be supplied from the cross tube of the adaptor by utilizing this gap.